Machine for producing pipe bends



May ZO, 1941. E. H. TAYLOR ETAL MACHINE FOR PRODUCING PIPE BENDS Filed May 6, 1940 3 Shqets-Sheet 1 INVENTORS ATTORNEYS May 20, 1.941.

E. H. TAYLOR ETAL, 2,242,332 MACHINE FOR PRODUCING PIPE BENDS 3 Sheets-Sheet 2 Filed May 6, 1940 wNQ ,a a JBY .256 M A v ATTORNEYS Patented May 20,1941 I omen STATES PATENT OFFICE MACHINE FOR rnonoomd PIPE BENDS Edward Hall Taylor and Joseph F. Staroba, Chicago, Ill., assignors to Taylor Forge & Pipe Works, Cicero, 11]., a corporation of Illinois Application May 6, 1940, Serial No. 333,566 9 Claims. (Cl. l53-48) This invention relates to pipe fittings, and has Figure 6 is a sectional view taken substantially to do with production of elbows, U-bends and on line 6-6 of Figure 5, on an enlarged scale, analogous articles by forcing straight tubular certain parts being shown in elevation; and

blanks over a suitably formed enlarging man-' Figure 7 is a diagrammatic view of the valve drel. actuating means for controlling operation of the Our invention is directed to a machine commandrel rod clamping devices.

prising a mandrel rod having an associated man- The machine is provided with a main frame l0,

drel, and means cooperating with said rod for in suitably constructed and braced, comprising upeflect forcing tubular blanks over the mandrel rights H, 52 and I3 spaced apart at each side by relative reciprocation of such means and the thereof and suitably anchored to an appropriage rod. In one form of our invention we provide a foundation. These uprights support, at the 1' machine having means for reciprocating a manupper ends, channel members I Q and Ma which drel rod and a mandrel carried thereby, such extend lengthwiseof the frame at the sides theremeans comprising alternately acting holding deof and, at their forward ends, are connected by vices spaced apart lengthwise of the mandrel 1 gusset plates IE to a cross member I6 of I -.beam rod for restraining it against lengthwise moveconstruction, these parts of the frame structure ment relative to the reciprocating means, while being secured together in any suitable manner, permitting placing of blanks upon the rod during conveniently by welding.

the draw stroke thereof for forcing the blanks A relatively thick plate i1 extends across the over the mandrel, to the end of increased speed main frame a short distance from ,the front in operation with resulting increase in producthereof and is secured to the channel side memtion and consequent reduction in cost of probers l8 and Ma in any suitable manner, conducing the blanks. More specifically, we provide,' veniently by welding. Mounting blocks l8, IS in conjunction with the holding devices, feeder and 20 are welded to the inner face of channel or pusher means for advancing blanks placed 2 member 14, between the cross member i6 and upon the mandrel rod forwardly along the latter, cross plate I1. Blocks l8 and 26 extend above in such'manner as to dispose the referred to 'member It, as does plate ii, the latter being blanks in front -of blank abutment means exprovided with side extensions lia seating upon tending about the rod, as the latter approaches the top flanges of channel members it and Ma. the limit of its forward stroke, thus assuring that 30 Similar mounting blocks l8 and 20 are welded the rearmost of such blanks will be disposed for to the inner face of channel member Ida but contact with the blank abutment means during are reversed relative to the blocks of member the rearward or draw stroke of the rod. Furid, in that the blocks 58 and 20 welded to ther objects and advantages of our invention member Ma extend downward beyond the latter will appear from the detail description. member. Two hydraulic cylinders 25 and 22 In the drawings: are suitably mounted, as by bolting, on, the Figure 1 is a central vertical lengthwise secmounting blocks of the channel members i' i and tional view of a machine embodying our inven- Ma, respectively, these cylinders extending tion, certain parts being shown in elevation and lengthwise of the frame in parallelism with the certain other parts being shown broken away. -channel members 16 and, Ida. Each of the the parts of the machine being shown in the cylinders is provided with a piston (not shown) positions which they occupy when the mandrel therein to which is secured a piston rod 23 slid rod starts its rearward stroke; able through appropriate stufling box means in Figure 2 is a view similar to Figure l but with the rear cylinder head, the piston rod 23 passing the mandrel rod in the position which it occupies through appropriate openings in the cross plate at the end of its rearward or draw stroke; ii. Figure 3 is a sectional view, on an enlarged The rearward ends of piston rods 23 are sescale, taken substantially on line 3-'-3 of Figure cured'to a cross head it in the form of a thick plate, which may be somewhat thinner than the 'Figure 4 is an end view of the machine, as stationary plate W. Cross head 26 is connected, viewed from the rear thereof, on the same scale by upper and lower channel members 25 and 26, as in Figure 3, certain parts being broken away; respectively, at each side thereof, to a yoke 27 Figure5 is a sectional view, on an enlarged disposed a considerable distance in rear of the scale, taken substantially on line 5-5 of Figure 1, cross head, to which the channel members 25 and certain parts being shown in plan; 26 are suitably secured, conveniently by welding,

' ciated therewith suitable means these channel members also being similarly secured to yoke 21. The cross head 24 and yoke 21, together with the connecting channel members 25 and 26 constitute a supplementary frame of substantially rectangular shape in plan. This supplementary frame is mounted for reciprocation lengthwise of the main frame, by means of slide rails 28 and 29 welded to the inner face of channel member 14, and a slide rail 99 welded to the inner face of channel member 14a. The yokemember 21 is provided with sions seating upon the upper faces of rails 28 and 99 for sliding movement lengthwise thereof, and with retaining clips 9| and 92 suitably secured to the yoke member, conveniently by bolting, and disposed to contact the under faces of slide strips 29 and 99, respectively. It will be understood that cross head 24 is likewise provided with suitable extensions seating upon the upper faces of slide strips 28 and 99, and with retaining clips extending beneath the slide strips 29 and 99. In this manner the supplementary frame appropriate extenis supported in the main frame for reciprocation lengthwise thereof. It will be understood that, within the broader concepts of our invention, the supplementary frame may be of any other suitable construction and may be slidably supported in any other suitable manner- The hydraulic cylinders 2| and 22 haveassofor admitting liquid under pressure thereto at either side of the pistons therein and for exhausting liquid from the other side of the pistons, for retracting and projecting the piston rods 29 and thus reciprocating the supplementary frame. Such means is well known and need not be illustrated nor described here in greater detail. While we preferably employ hydraulic means of the character referred to for reciprocating the supplementary frame, any other suitable means may be employed for that purpose.

Yoke 21 is provided with a central slot 95 extending downward from its top and disposed in alignment, lengthwise of the frame l9, with an opening 96 through cross head 24 and an opening 91 through the openings 96 and 91 receive a mandrel rod 98 of a length to receive a plurality of straighttubular blanks 99 and to extend forwardly beyond frame l9 into a hood or furnace 49 of refractory construction. A suitably formed curved enlarging mandrel 42 is secured on the forward end of rod 98 within furnace 49. Suitable means, such as one or more gas burners 41, is provided for heating blanks on the mandrel 42 and rod 98. Preferably, a grooved roller 44 is supported by a bracket secured to the back wall of the furnace, in position'to support the mandrel rod and the blanks thereon. Furnace 49 is suitably mounted on wheels 45 traveling upon rails,- one of which is shown at 46, extending forwardly from frame 19 in alignment therewith. An apertured plate 41 is secured to the back of furnace 49 and receives a finger 48 extending downward from the forward end of a furnace draw bar 49, the rearward end of which extends through an arm 59 and depending from cross head 24. Two nuts 5| and 52 are screwed upon the rearward end portion of draw bar 49 and contact the forward and rearward faces, respectively, of arm 59. The

secured to furnace is thus connected to cross head 24 for' movement therewith effective to maintain constant the relation between the furnace and the mandrel rod and mandrel carried thereby.

fixed stop plate 11. Slot 95 and bar 61 meshes with two stop toward plate 11, and the lower stop 55 is provided, at its lower end, with a rearwardly extending weight element 58 which urges this stop toward plate l1. In this manner the stops 55 and 56 normally are held in contact with a spacing member 59 secured to the front of plate l1 around opening 91, plate l1 being effective for preventing rearward movement of the stops 55 and 56 from their normal position. During. the yreargward or draw stroke of mandrel rod98, the rear ward end of the most rearward or last blank 99 on this rod, in advance of the stops55 and 56,ii'sin contact with these stops so that, during the rearward travel of rod 98, the blanks are successively forced over the mandrel 42 as a continuous operation. During mandrel rod further blanks are loaded thereon and, subsequently, are advanced forwardly along the mandrel rod and move into position in front of the blank stops, as will be described presently.

The reciprocating frame is provided with holding devices alternately operated in opposite relation, for securing the mandrel rod to the reciprocating frame for movement therewith and restraining the rod against movement relative to the reciprocating frame, to facilitate charging the mandrel rod with blanks. The holding means referred to preferably is in the form of two clamping devices, 24 and the other associated with yoke 21. The latter clamping means will be described first, with particular reference to Figure 4. A hydraulic cylinder 69 is suitably mounted on the lower portion of yoke 21, at the rear thereof, as by means of an associated mounting frame structure 6| bolted to yoke 21. This cylinder has a piston (not shown) slidably mounted therein, to which is secured the lower end of a piston rod 62 slidable through a stufflng box structure 69 at the upper end of cylinder 69. Piston rod 82 is ad- 'justably secured at its upper end, by means of a screw rod 64 and associated jam nuts 65 and 66, to the lower end of a double rack bar 61. Rack segments 68 pivoted on pins 69 mounted in yoke 21 and in a keeper plate 19 bolted to the yoke. An arm 1| extends upward from each of the segments 68 and carries, at its upper portion, a clamping jaw 12 appropriately recessed to fit about the mandrel rod 98 in clamping engagement therewith- The area of rod 98 Two blank abutment members or stops -55 and corresponding to the jaws 12 is provided with a plurality of circumferential ribs 19, the rod engaging face of each jaw'12 also being provided with a-plurality of ribs disposed for interengagement with the ribs 19. When the double rack bar 61 is moved downward into its position shown in Figure 4, the clamping blocks or jaws 12 are closed tightly about mandrel rod 98 and serve to support the rearward end of this rod while also securing it to yoke 21 for movement therewith. The ribs on the clamping blocks 12, being disposed in interengaging relation with theribs 19 on the mandrel rod 98, positively restrain this rod against lengthwise movement relative to the reciprocating frame.

Cross head 24 also is provided with clamping means for supporting and gripping the mandrel rod 98. A hydraulic cylinder 69a is bolted to a this rearward stroke of the one associated with cross head suificiently to clear block the position shown scribed in detail.

supporting bracket 24a suitably secured to and extending rearward from the lower portion of cross-head 24. The piston rod of cylinder 68a is adjustably secured to a lower clamping block slidably mounted between cross head 28 and a keeper plate 16 bolted to the back of cross head 24. Clampingblock 15 cooperates with an upper clamping block 11 slidably mountedbetween cross head 24 and an upper keeper plate 16a. Block 11 is operated by means of a screw shaft 18, rotatably mounted through a bracket plate 24b secured to cross head 26, suitable means being provided for restraining shaft 18 against endwise movement. A hand wheel 18a is secured on the upper end of shaft 1% for rotating the latter. Each of the blocks 15 and 11 has a surface shaped to fitabout rod 38 and is provided with spaced ribs disposed for interengagement with ribs 19 extending circumferentiallly of rod 38, at the area thereof corresponding to the associated clamping blocks. Block 11 is adjustment for engagement about the corresponding portion of rod 38, and thereafter remains in that position, the rear clamping jaws 12 then being slightly lower than block 11. When the lower block 15 is moved downward into releasingposition, ,the rod 33, owing to its length between roller 33 and clamping -jaws 12, sags downward 11, into substantially in Figure 2. Upon raising of the block 15 the corresponding portion of rod 38 is raised by the latter block into .engagement with block 11 and clamped between blocks 15 and That causes slight upward bowing of the portion of rod 38 between the blocks 15 and 11 and the rear clamping jaws 12. Shortly therev after the jaws 12 are opened and moved laterally away from the rod 38 sufficiently to clear the latter, the rearward end of which then rises slightly into the position shown in Figure 1. In the releasing position of block 15 the latter block and block 11 are spaced apart to provide clearance about mandrel rod 38, sufiicient to accommodate a blank moved forward along this rod and, also, to permit movement therebetween of a pusherdevice; as will be explained later. It will be noted that the clamping blocks 15 and 11 are of greater thickness than the rearward clamping laws or blocks 12. That is desirable since, as will appear more fully later, the forward clamping device is used for supporting and holding the mandrel rod 38 during the draw or rearward stroke thereof and, accordingly, is subjected to more severe stresses than the rearward clamping device.

Each of the cylinders 89 and 68a is provided with' means for admitting thereto liquid under pressure, from a suitable source of supply, at either side of the piston and for exhausting liquid from the cylinder at the other side of the piston, for moving the piston in desired direction and opening and closing the clamping devices as required. Means of the character referred to is known and need not be illustrated nor de- Such means may comprise a suitable valve within a valve housing 85 carried by the cylinder, the latter having appropriate ducts or passages cooperating with the valve within housing the liquid. Two lengths of flexible hose 85 and 81 may be connected to the valve housing 85 for admission and exhaust of liquid to and from the cylinder. Conveniently, sheet metal plates 88 and 89 are provided at the sides and adjacent the bottom of the main frame, defining a boxing in which the flexible hose lengths may lie, resting upon the bottom plate 89.

In order'to assure operation of the clamping devices in suitable timed relation, means is provided for actuating the control valves of the cylinders 60 and 60a responsive to reciprocation of the mandrel rod and the reciprocating frame. To that end, an arm 90 is secured, at its inner end, to valve stem 9! extending through the top wall of housing 85. Arm 90 is provided, at its outer end, with a vertically. extending pin 92 connected by an over center tension spring 93 to a pin 94 secured in the top Wall of valve housing 85 in rear of valve stem 9|. Each of thepl ns 92 cooperates with a pair of trip fingers 95 and 96 secured to and projecting inward from the adjacent side. wall 88 of the boxing The trip fingers'are so disposed that, as the reciprocating carriage reaches its forward position shown in Figure 1, pin 92 of cylinder 80a contacts trip finger 95 93 passes beyond the center of valve stem 31, after which spring 93 completes" the throw of arm 98, effective for turning the valve within housing 85 into positionto cause closing of the forward clamping device about mandrel rod 38 for supporting and gripping the latter. Immediately thereafter arm 90 associated with cylinder 38 is similarly operated, by contact of its pin 92 with the associated trip finger 95, and serves to cause opening of the rearward clamping de vice. In that respect, it will be noted that the valve means of the cylinders 60 and 68a operate in opposite relation, the turning of the valve of cylinder 69a serving to cause the reciprocating frame is in its forward position shown in Figure l, the most rearward blank 39 on 85 for controlling desired flow of s mandrel rod 38, in front of the blank stop members 55 and 58, is spaced a short distance in advance of such members, as shown, and the mandrel rod 38 is secured to the reciprocating frame by means of the forward clamping 'device which,

stroke of the reciprocating frame, which is its rearward stroke, the rearward end of blank 33 on rod 33, in advance of and adjacent the stop members 55 and 58, is moved into contact with these stop members, and during the continued rearward movement of the mandrel rod with the reciprocating frame. which is its draw stroke, the blanks are forced over the mandrel in the manner previously described.

The distance between the forward clamping device and yoke 21 is somewhat greater than twice the length of one of the tubular blanks 33. During the, draw stroke of the mandrel rod and the reciprocating frame, two blanks may be placed on the rearward portion of mandrel rod 33, over the rearward end thereof, as indicated ing device. In that manner no time is lost in associated therewith, causing turning jaws of the forward-'clampcharging the mandrel rod with the blanks, since such charging is done during the draw stroke of the rod. The machine illustrated is what might be termed a short stroke machine, having a draw stroke approximately equal to twice the length of one of the blank' For that reason, two blanks are placed upon the mandrel rod during the draw stroke, in the manner previously described. Obviously, if the machine were made to have a different length of stroke, the number of blanks placed upon the mandrel rod during its rearward stroke would be varied accordingly. As the reciprocating frame approaches the end of its rearward stroke, the valve of cylinder 60 is actuated, by the associated trip finger 96 and tension spring 93, to close the rearward clamping device. after which the valve of cylinder 60a is actuated, by its associated trip finger 98 and tension spring 83, to open the forward clamping device. At that time the cylinders 60a and 60 occupy the relative positions shown in dotted lines in Figure 'l, the full line positions of these cylinders being those which they occupy when the reciprocating frame is in its forward position shown in Figure 1. With the reciprocating frame in its rearward position the forward clamping device is open, two blanks are disposed upon mandrel rod 38 between the forward clamping device and the rearward clamping device, and the rearward end ofthe mandrel rod is supported and secured by the latter clamping device. The reciprocating frame is then moved forwardand carries with it the mandrel rod 38. During such forward movement of the reciprocating frame the two blanks on the rearward portion of rod 38 are moved forward along the latter, by means position in front of the forward clamping de.-- vice, this movement of the blanks preferably being such that when the reciprocating frame [reaches its forward position shown in Figure 1 blanks placed upon the rearward portion of the rod 38 the ,two

will have been moved into position in front of the blank stop members 55 and 86. The forward clamping device'is then closed and the rearward clamping device is opened, in the manner above described, and the reciprocating. frame is moved rearward moving with it the mandrel rod for performing the draw stroke of the latter.

A rack bar I is secured to channel member I4, at the inner face thereof, by bolting or in any other suitable manner, this rack bar extendin lengthwise of channel member I4 at .the midportion thereof. A guide member 'IOI (Figures 5 and 6) provided with supporting arms I02, as shown in Figure 1, isbolted to tire channel members 25 and 28 of the reciprocating frame and slidably supports a reciprocating rack bar I03.

.The latter is retained in guide member I0 I, by

retaining strips I03 bolted to the inner face of guide member IM and defining between them a slot I05, strips I04 overlying the up er and lower flanges of the head of rack bar. I03 which, as-

shown in Figure 6, is of T-shape in cross section. Rack bar I03 also is slidable in a guide member I01, similar to guide member IOI, bolted to mounting blocks I9 and 20 secured to the inner face of channel member I4. Retaining strips I03 a, bolted to the inner side of guide member I01, overlie the head flanges of rack bar I03 and define between them a slot I05a aligned with slot I05; defined by the retaining strips I03 associated with the guide member IN. The latter guide member is provided, adjacent its forward to be described presently, into lower walls of. guide member IOI.

end and through its outer side, with an opening IIO (Figure 5) through which extends a compound pinion mounted for rotation about a vertical axis by means of a stub shaft III, the end portions of which extend into the upper and the The compound pinion comprises a lower pinion I I: which meshes with rack bar I00, and an upper pinion II3 of increased diameter which meshes with rack bar I03 and overlies rack bar I00, out of mesh therewith, it being noted that rack bar I33 is disposed somewhat higher than rack bar I33, as shown in Figure 6. Preferably pinion II3 has twice as many teeth as pinion II2 so that rack bar- I03, while it moves in the same direction as the reciprocating frame, travels twice as fast as the latter frame. in the reciprocationithereof.

An angle bracket H5 is bolted to the inner side of rack bar I03 for movement therewith, this bracket operating in the slots I05 and IIIIa and extending therefrom inward toward the mandrel rod 38, in the plane of which rack bar I03 is disposed. A pusher H6 is pivoted at its rearward end, at 1, to the bracket II5. This pusher is shaped at its forward end to fit about the side portion of mandrel rod 38 and is normally held in contact therewith by a coil compression spring II8 confined between the forward portion of the pusher and the face of bracket II5. Suitable means, such as studs entering the end portions of the spring II8 may be provided for retaining the latter in position. In its normal position the pusher III; is inclined inward and forward relative to the mandrel rod 38, as shown in Figure 5.

It will be understood that the pusher H3 is reciprocated similarly to the reciprocating frame but at twice the speed thereof. In order to permit of this movement of the pusher H8 and bracket II5, the stop plate I! is provided with a slot H81; therein extending from opening 31 thereof, cross head 24 is provided with a slot III extending from opening 36 thereof and the upper and the lower jaws of the forward clamping device are spaced apart to define therebetween a slot I20, these three slots being disposed in alignment and of appropriate size to accommodate the bracket H5 and the pusher II3.

In the rearward position of the reciprocating frame, shown in Figure 2, the pusher III is disposed'in rear of the second or rear blank 33 placed upon mandrel rod 38, between the forward clamping deviceand yoke 21 of the reciprocating frame. In the forward movement of this frame the pusher also travels forward, but at twice the speed of the frame and the mandrel rod 38. The pusher thus operates to move the two blanks 39 forward along rod 38, through cross head 24 and stop cross plate I'I,

into position in front of the blank stop members 55 and 56, by the time the mandrel rod has been moved into its forward position shown in Figure 1. At that time the two blanks 33 have been moved from the rearward portion of rod 33 to a position in front of the stop members, shown in Figure 1, and the reciprocating frame is now ready to start on its rearward stroke. In the forward movement of the blanks along the' mandrel rod 38, the blank stop members are swung forward on theirpivots to permit passage between them of the advancing blanks, after which the stop members are returned to their normal position by, the associated weight elements, in the manner previously described. As the reciprocating frame reaches its forward position the forward clamping means is closed and the twice the turned to the pusher operates at described, of the reciprocating is moved fram forward the rearward movement 2,242,332 rearward clamping means is opened, as above and in the succeeding rearward stroke e the mandrel rod 38 therealong in the manner described. In

of the reciprocating frame the pusher also moves rearward, butat the rearward end of the the mandrel rod frame reaches its rearwar speed of the frame, and isthus reits rd position, for contacting second blank placed on 38. when the reciprocating (1 position.

It will be appreciated that the rate of travel of the pusher relative to that of ing frame may be varied the blanks into position clamping means prior to the reciprocatsomewhat, so long as sumcient speed to move in front of the forward closing of the latter.

Preferably the blanks should be moved into position in advance of the b iank stop members 55 and 65, as stated, though that is not essential to thereabout and res the broader concept of the blanks be advanced of the forward clamping thereof, they may be mo our invention, since, if into position in front means prior to closing ved manually further along the mandrel rod into desired position. It

apmnded claims, in this the preferred form only been disclosed.

We claim: 1. In a machine for mandrel rod for receiving we intend to include all within the scope of the application in which of our invention has producing pipe bends, a

tubular blanks, blank abutment means movable toward and away from said rod normally held rearward from normal the forward end of said trained in position extending against movement position, a mandrel at rod, means for reciprocating said rod comprising two holding devices in rear of said abutment lengthwise of said rod means spaced apart and efiective for holding it against endwise movement relative to said reciprocating means, rearward holding device and then moving the releasing position limit ofdts rearward strok means for first moving the into holding position forward holding device into as said and approaches the e and for first moving the forward holding device into holding position and then moving the rearward holding device into releasing position as said rod approaches tile limit of its forward stroke, and means for moving blanks placed ing devices forward along said rod into position in front of said forward holding device during and responsive to the forward stroke of said rod.

2. In a, machine for nandrel rod for receiving ending thereabout and producing pipe bends, a

on said rod between said holdtubular blanks, blank. abutment means movable toward and away from aid rod normally yieldingly held in position exrestrained against movement rearward from normal position, a mandrel .t the forward end of said rod, means for 'reiprocating said rod com evices in rear of said ab part lengthwise of said olding it against endwise rid reciprocating means, aciprocation of said rod prising two clamping utment means spaced rod and effective for movement relative to means responsive to for first closing the forward clamping device rearward clamping device and then opening the as said rod approaches the limit of its rearward stroke and'for first closing the forward clamping device and then opening the rearward; clamping device as said rod approaches the limit of its forward stroke,

and means for moving blanks placed on said rod between said clamping devices forward along said rod into position in. front of said abutment means during the forward stroke of said rod.

3. In a machine for producing pipe bends, a

vmandrel rod for receiving tubular blanks, blank abutment means movable toward and away from said rod normally yieldingly held in position extending thereabout and restrained against movement rearward from normal position, a mandrel at the forward end of said rod, means for reciprocating said rod comprising two clamping devices in rear of said abutment means spaced apart lengthwise of said rod and effectiveior holding it against endwise movement relative rearward clamping device and then opening the forward clamping device as said rod approaches the limit of its rearward stroke and for first closing the forward clamping device and then I vopening the rearward clamping device as said rod approaches the limit of its forward stroke, moving blanks placed on saidrod clamping devices forward along said rod into position in front of said abutment means during and responsive to the forward stroke of said rod.

4. Ina machine for producing pipe bends, a main frame, a cross-member fixed in said frame,

-a reciprocating frame mounted in said main frame in rear of'said member, a mandrel rod carried by said reciproand then opening the forward clamping device as said reciprocating frame approaches the limit of its rearward stroke and for first closing the forward clamping device and then 'opening the rearward clamping device as said reciprocating frame approaches the limit of its 5. In a machine for producing pipe bends, a main frame, across-member fixed in said frame, [a reciprocating frame mounted in said main bar fixed to said main frame,

normal position, a mandrel at the forward end of devices carried by said remeansactuated by reciprocationof said reciprocating frame for moving blanks placed on said rod between said clamping devices forward along said rod during the forward stroke of the latter into position in front of said forward clamping means.

6. In a machine for producing pipe bends, a mainframe, a cross-member fixed in said frame, a reciprocating frame mounted in said main frame in rear of said member, a mandrel rod for receiving tubular blanks extending through said reciprocating forward beyond the latter, blank abutment means carried by said cross-member movable toward and away from said rod normally held in position extending thereabout and restrained against movement rearward from normal position, a mandrel at the forward end of said rod, two clamping devices carried by said reciprocating frame spaced apart lengthwise of said rod and alternately clamping it, means responsive to reciprocation of said reciprocating frame for first closing the rearward clamping device and then opening the forward clamping device as said reciprocating frame approaches the limit of its rearward stroke and for first closing the forward clamping device and then opening the rearward clamping device as said reciprocating frame approaches the limit of its forward stroke, and rack and pinion means acutated by reciprocation of said reciprocating frame for moving blanks placed on said rod-between said clamping devices forward along said rod during the forward stroke of the latter into position in front of said forward clamping means.

'7. In a machine for producing pipe bends, a main frame, a cross-member fixed in said frame, a reciprocating frame mounted in said main frame in rea'r of said member, a mandrel rod for receiving tubular blanks extending through said reciprocating frame and said cross-member and forward beyond the latter, blank abutment means carried by said cross-member movable toward I and away from said rod normally yieldingly held frame and said cross-member and in position extending thereabout and restrained againstmovement rearward from normal position, a mandrel at two clamping devices carried by said reciprocating frame spaced apart lengthwise of said rod and alternately clamping it, means responsive to reciprocation of said reciprocating frame for first closing the rearward clamping device and then opening the forward ciprocating frame approaches the limit of its rearward stroke and for first closing the forward clamping device and then opening the rearward clamping device as said reciprocating frame approaches the limit of itsforward stroke, a rack a reciprocating rack bar, diiferential drive means carried by said reciprocating frame for reciprothe forward end of said rod,

clamping device as said re-' between said 'bars end of a blank on said rod between said clamping devices when said reciprocating frame is at the limit of its rearward stroke.

8. In a machine for producing pipe bends, a main frame, a cross-member fixed in said frame, a reciprocating frame mounted in said main frame in rear of said member, a mandrel rod for receiving tubular blanks extending through said reciprocating fraime and said cross-member and forward beyond the latter, blank abutment means carried by said cross-member movable toward and away from said rod normally yieldlngly held in position extending thereabout and restrained against movement rearward from normal position, a mandrel at the forward end of said rod, two clamping devices carried by said reciprocating frame spaced apart lengthwise of said rod and alternately clamping it, means responsive to reciprocation of said reciprocating frame for first closing the rearward clamping device and then opening the forward clamping device as said reciprocating frame approaches the limit of its rearward stroke and for first closing the forward clamping device and then opening the rearward clamping device as said reciprocating frame approaches the limit of its forward stroke, a rack bar fixed to said main frame, a guide member carried by said reciprocating frame, ing rack bar mounted in said guide member, a compound pinion carried by said guide member comprising a first pinion meshing with said fixed rack bar and a second pinion of greater diameter than said first pinion meshing with said reciprocating rack bar, and a pusher member carried by said reciprocating rack bar movable toward and away from said mandrel rod and disposed to engage the rearward end of a blank on said rod between said clamping devices when said reciprocating frame is at the limit of its rearward stroke."

I 9. In a machine for producing pipe bends, means for forming tubular blanks by relative endwise movement between the blanks and an interior forming mandrel, said means comprising a first member in the form of a mandrel rod having a forming mandrel at its forward end and a second member having blank stops movable toward and away from said rod normally extending thereabout, one of said members being reciprocated relative to the other, the stroke of said one member in one direction constituting its draw stroke effective for causing relative endwise movement between said rod and blanks thereon in front of said stops, the stroke of said one member in the opposite direction constituting its return stroke, forward and rearward clamping devices engageable with said rod spaced apart lengthwise thereof in rear of said stops, means for closing said rearward clamping device and opening said forward clamping device and vice versa, as said one member approaches the limii ofits draw stroke and its return stroke respectively, and means for advancing along said roc responsive to the return stroke 'of said one member blanks placed on said rod between said clamping devices.

EDWARD HALL TAYLOR. JOSEPH F. STAROBA.

a reciprocat- 

